Ptolemy XIII

Ptolemy XIII Theos Philopator (62 BC-13 January 47 BC) was Pharaoh of Egypt from 51 to 47 BC, succeeding Ptolemy XII and Cleopatra and preceding Cleopatra and Ptolemy XIV. Ptolemy fought against his sister Cleopatra in the Alexandrine Civil War and was forced to marry her by Julius Caesar. He drowned while retreating at the Battle of the Nile.

Biography
Ptolemy was the son of Ptolemy XII, and he succeeded to the throne in 51 BC by marrying his sister Cleopatra. The eunuch Pothinus served as the young Ptolemy's regent, while his tutor Theodotus of Chios and the general Achillas also served as co-regents. In 48 BC, the influential and power-hungry Pothinus persuaded Ptolemy to attempt to depose Cleopatra, whose power as queen was rising. Cleopatra's face appeared on coins and her names appeared on documents, while Ptolemy was not on either; he grew resentful of his sister's influence. She was forced to flee to Syria, but she gathered an army and returned to Egypt, starting the Alexandrine Civil War. In addition, their sister Arsinoe IV of Egypt also laid claim to the throne, further complicating the situation.

Downfall at the Nile
That same year, Julius Caesar and his Roman army landed in Egypt with the goal of hunting down Pompey the Great, as well as settling the dispute between the two rulers, as Ptolemy XII's will had instructed him to do. Pothinus had Ptolemy's severed head presented to Caesar as a gift, but Caesar was disgusted and angered, as he had intended to show mercy to his respected rival and former son-in-law. This mistake led to Cleopatra winning Caesar's favor and becoming his mistress, and Caesar had Pothinus executed before marrying Cleopatra. Caesar also had Ptolemy and Theodotus sent to join Achillas' army, which had been besieging Alexandria with the goal of overthrowing Cleopatra. Ptolemy was excited, as he believed that this meant that Caesar had decided to save him, but Theodotus knew that they were being sent to their deaths, as the army was being surrounded by Roman and Bosporan armies. At the Battle of the Nile, Ptolemy and Arsinoe's armies were defeated, and Ptolemy drowned while attempting to cross the Nile. His younger brother Ptolemy XIV became the de jure co-ruler of Egypt, with Cleopatra and Caesar exercising all of the power.